Vehicle body and fender straightening apparatus



VEHICLE BODY AND FENDER STRAIGHTENING APPARATUS Filed June 18, 1948 w 3%, 1950 F. W. BOWIE ET AL 2 Sheets-Sheet l May 30, 1-950 F. w. BOWIE ET AL. 2,509,330

VEHICLE EDDY AND FENDER STRAIGHTENING APPARATUS Filed June 18, 1 948 2 Sheets-Sheet 2 F AN KW Bow: E ErJwA wpNfimgpsv/w onmeq Patented May 30, 1950 VEHICLE BODY AND FENDER STRAIGHTEN- ING APPARATUS Frank W. Bowie and Edward N. Sturdevant, Binghamton, N. Y.

Application June 18, 1948, Serial No. 33,688

8 Claims. (01. 153-32) This invention relates to an apparatus for use on the sheet metal parts of motor vehicles, such as the top and mud guards, for straightening dents and other distortions occurring due to accidents.

Numerous types of devices and mechanisms have been employed for straightening out sheet metal portions of motor vehicles. For many years, this work was performed purely through the use of hand tools, rollers, etc., and this method was not found to be particularly satisfactory. An apparatus in common use at the present time for performing the functions referred to is illus- 'trated and described in the F. J. Hauschild Patent No. 2,148,943. In such patent, a yoke possessing a reasonable degree of resiliency is provided with means at one end thereof for supporting a dolly in contact with the side of the work opposite that at which pressure is to be exerted, and such pressure is applied through the medium of a ram' reciprocated by a suitable air motor to be impacted against the work supported by the dolly. A bell or plate surrounds the ram and is held in firm engagement with the work as supported by the dolly, and the only resilience inis to provide an improvement over the structure shown in the Hauschild patent referred to wherein the work is more effectively cushioned with respect to the elements between which it is clamped, thus providing for a smoother operation of the apparatus and the accomplishing of more efficient results.

A further object is to provide such an apparatus wherein the work is clamped between a suitable dolly and an ironing ring in which the ram is operable, and to so mount the ironing ring relative to the air motor as to provide an improved cushioning action and to permit part of the smoothing work to be effectively performed by the ironing plate.

A further object is to provide novel means for utilizing air pressure rather than a mechanical clamping means for fixing the Position of the air motor relative to the work, thus rendering wholly feasible the use of an ironing plate in conjunction with the ram and increasing the facility with which the apparatus may be used as well as improving the results obtained.

A further object is to provide an apparatus of this character wherein the air motor has associated therewith a cylinder carrying an ironing plate surrounding the ram, the cylinder being so mounted as to be freely longitudinally movable for adjusting the apparatus relative to the work, the cylinder being urged toward the work by air pressure during the use of the apparatus to hold it in position relative to the work while cushioning its movement instead of fixing it positively in an adjusted operative position.

Other objects and advantages in the invention will become apparent during the course of the following description.

In the drawings we have shown one embodiment of the invention. In this showing:

Figure 1 is an end elevation of the apparatus.

Figure 2 is a side elevation of the same.

Figure 3 is an enlarged detail perspective view of the ram and ironing plate, the parts being shown separated.

Figure 4 is an enlarged axial sectional view through the power head of the apparatus, parts being broken away and parts being shown in elevation.

Figure 5 is a detail sectional view on line 5-5 of Figure 4, with the air motor piston raised from the position shown in Figure 4.

Figure 6 is a transverse sectional view on line 6-6 of Figure 4; and

Figure 7 is a detail perspective view of the motor cylinder.

Referring to Figures 1 and 2, the numeral H] designates a tubular yoke of the general type disclosed in the Hauschild patent referred to above, this yoke possessing a small degree of resiliency. A suitable fitting II at one end of the yoke supports a dolly I2, which may be of any desired type according to the work being performed. It will be obvious that the dolly is purely conventional and any desired form of such ele- -ment may be employed.

The opposite end of the yoke fits within a sleeve M of a cylindrical tool holder I5 having its axis arranged in alignment with the axis of the other end of the yoke Ill. The yoke is fixed in the sleeve by tightening a suitable wing nut IE or any other desired type of fastening means.

Referring to Figure 4, it will be noted that the cylindrical tool holder l 5 has an internal annular flange E8 at its lower end forming a cylindrical bearing in a manner to be described. Between the upper and lower ends of the tool holder 15, an internal annular flange I9 is formed integral with the tool holder, and the two purposes of this flange also will be described below. At its upper end, a cap, 20 isthreaded into the tool holder and is provided. with a: suitable fitting 2l for connecting the cap '20 to a hose 22 leading to a suitable source of compressed air controlled in the usual. manner by a hand or foot valve (not shown) The cap 26 is provided with a cylindrical depending" extension 24 of substantial length as viewe'din; Figure 4 and having an air passage.25 extending entirely therethrough for the flow of'airunder pressure from the hose 22.

A cylinder 28 is mounted to slide ..axially"inrthe-= flanges l8 and I9, these flanges serving; as bearings for the cylinder 28. end, the. cylinder 28 is provided with an eX- tern'al"fiange"2'9 a'dapted'to engage the top of the flange i9fto limit-downward movement of the cylinder '28. Thefl'ange l9 thus functions both as. a bearing for the cylinder"28 and as means for limitingdownward' movement of such cylinder; From thefiangezfito' its lower extremity," thecylinder28 isof'uniforrn external diameter except" asreferred to below, andaccordingly'it will'b'e'a-pparent'that'the cylinder 28 is insertable intothe' tool holder' l from' the upper en'dthereof prior to the application of the cap 20'.

A cap'32 istlireadedin the upper endof the cylinder 28..and"is.providedwith an external flange33 'se'atingupon'the top end of the cylinder 1 28.. The.- lower; en'dof" the'axial" extension 24 projects into thecap'32 andis'sealed relative to the can by a suitable sealing'ringg34.

The cap 32 is provided with'adep'ending cylindr 36having'a.bottom"wall"31'defining the lower limit of a'cylindrial chamber 38-'th'erein.- This chamber receives the'lower end of the-axial 'projection'. 24 up'on" upward movement "of the cylinder 28, it will" become "apparent that such upward movementof'the cylindermay be accomplished by, hand. when the chamber 38 is not connected to the source. of air pressure.

The cylindrical portion 36" of the cap 32' is provided'with' radial openings All communicating with an external annular groove 4| turned" in the cylinder136. This groove, when the-parts areassembledes in"Figure 4;ris in direct registration with an internal annular groove 42 formed within the upper end portionof the cylinder 285 The groove 42, in turn, communicates with one'or more longitudinally extending passages 43'- dr'i1led in the wall of the cylinder 28 and-communicating at its 'lower endiwith an internal annular groove "formedin the innerwall' of the cylinder 28 at a point spacedsubstantially-below the wall 31.

A. piston 48Yismounted to reciprocate-in the cy1inder28 and is .provi'dedwith an axial bore in its upper endcommunicating with'radi cal'passages 5fl'(Figurest4"and 5). As will become apparent, the passagesjfl. when the piston 48is adjacent its upper limit of movement, communicate with the annular groove 44 for the flow. of compressed air therefrom into the'upper end. af, the cylinder 28, beneath the wall 31. When the piston. 48...is at its lower limit of movementas. shown inFigureAi the "groove 44 communicates with. radial passages 52; These passages communicate. with the'upper ends of longidownwardly through thelength ofthe piston 48 Adjacent its upper 4 to communicate with the bottom of the cylinder 28 beneath the piston 48 to urge the latter upwardly.

The tool holder I5 obviously is provided between the flanges l8 and IS with a chamber 56, and this chamber communicates with the interior of the cylinder I 8 above the piston 48 through one or more radial' passages? 51. These; passages are open to the cylinder 28above the piston 48 when the latter is at its lower limit of movement, but are covered by the piston as the latter moves upwardlyi: Thewchamber 56 may communicate with the-atmosphere through an exhaust port 58 drilled through the tool holder l5, or it may communicate ;w.ith'the atmosphere through passages 59 formed by milling fiat surfaces 6!! on the outer surface:ofrthemylinder 28 as shown in Figures 4 and '7. In the latter figure it will be noted that two*of"the exhaust ports 51 have been shown, and such ports have been found ample for the exhausting-"of air' pressure from above" the-piston d8; Similar exhaust portsifil are drilled through the cylinder 28 to': exhaust'v the; bottom of the cylinde'r 28' beneath thepis'ton. when the latter moves upwardly.

The-lower end: of-'th'e.cylinder" 28 is'iaxially recessedas a'5 55 to :receive' 'an'upwardly extending cylindrical sleeve. 65 externally flanged at its lower=endas at 67 'to1be-secured to an'ironing plate685 This *plate. is :sh'ownzin the present instancerfor example in'Fi'gure 3, as being circular in form' and as having '2; depending circular roundedflange-69' onithe. bottom face thereof. A snap ring lfliis -arrangedIin'a groove 1 l=formed in th'elexternalsurface of the cylinder'2fi 'adj'acent the lower end thereof; and a roundeended pin 'IT isca-rried by the snap ringeandfen'gagea-ble in an'annular "groovezlis" formed in" the'outer surface of thesleeve- 66. The round end. of the pin 12 serves-tofrictionally holdithe sleeve 66 in position while permittingrits ready "removal and insertion by the proper. application of "endwise forces to the sleevefifi.

A ram 15"is 'reciprocable in thesleeve 66"and is provided With'an external flange 16" receivedin an internal groove-ll'formed in the sleeve 65. The"- length' of the" groove 11 is substantially greater'thanthe width of theflange 16 to permit the latter to-move axially relatively freely in the body'of the cylinder- 28 to slida'bly'receive an axial extension 19 formed on theupper endof the ram 15 and engageablewith the lower end of anlaxial extension 'carried by the piston 48 and projecting downwardly through the-bearing 18.

Operation A'lsuitable dolly" I2 is connectedto the .lower arm of. the yoke-v 1 Land in placing the apparatus in position for operation, the operator will manually" push. theylinder" 28 and ironing plate 68 upwardly'until the. wall 131 v (Figure 4) 1 contacts with the lower end of the tube 24.. Before air is turned intoithexhose-zz; the cylinder 28 may be: freely pushed-upwardly inthe manner and for th'e purposestated. Whenthe apparatushas been :placed in: properposition :relative to the work',.ith'e-cylinder ZB'may be moved downwardly -toengage-"the flange 69"ofthe ironing plate 88 withthe surface of the rmetal on which work is to be performed. This engagement of the ironing plate withthe'work willtake place with the flange 29"sp'aced above'theflange I9, and

i accordingly there will beno positiveenga ement between the cylinder 28 and the tool holder l through which endwise movement of the cylinder 28 is prevented.

, With the apparatus thus placed in position relative to the work, air will be turned into the hose 22 and will flow through passage 25 into the chamber 38. The air will also flow through passages 48 into grooves 4| and 42 and thence through passage or passages 43 into the groove 44. It will be apparent that the pressure in the chamber 38 will exert a downward force on the wall 31, and this force is communicated through the cap 32 to the cylinder 28 to urge the latter downwardly and thus maintain the ironing plate 68 in engagement with the work. Obviously this engagement is maintained solely by the elastic air pressure and not through any positive fixing or clamping of the cylinder '28 relative to the tool holder Hi. This is an important feature of the present apparatus.

Assuming that the piston 48 is initially in the position shown in Figure 4, the groove 44 will communicate with the passages 52 and 53 to supply compressed air to the cylinder 28 beneath the piston 48. At the same time, the passages 50 will be out of communication with the groove 44 while the passages 51 will be open to the space above the piston 48 to exhaust such space to the atmosphere. Under such conditions, the piston 48 will be moved upwardly by the air pressure therebeneath.

As the piston 48 moves upwardly, the passages 52 will move out of communication with the groove 44 to cut off the supply of air pressure to the bottom of the cylinder 28 beneath the piston 48. At approximately the same time, the piston 48 will close the exhaust ports 51, after which the space beneath the piston 48 will be exhausted to the atmosphere through ports Bl, thus releasing the force tending to move the piston 48 upwardly. At approximately the same time the exhaust ports 6! are opened the passages 58 will move into communication with the groove 44, thus admitting air pressure into the space above the piston 48. Inasmuch as the inertia of the piston 48 will carry it beyond the point at which initial full communication is established between the passages 50 and groove 44, this grOOVe is made substantially wider than the diameters of the passages 5|], as shown in Figure 4.

Upon the connection of the space above the piston 48 with the source of pressure in the man ner stated, the piston 48 will start to move downwardly. During such downward movement, the passages 58 will move out of communication with the groove 44; the exhaust passages 51 will be uncovered; and the exhaust passages 6| will be covered, the latter operation occurring before the piston 48 reaches the lower end of its stroke. The inertia of the piston 48 will carry it to its lower limit of movement and since the end of the cylinder 28 beneath the piston 48 will be momentarily closed both to the exhaust ports 8i and to the intake ports 52 for a limited period, the pocketing of air in the cylinder 28 beneath the piston 48 will somewhat cushion the movement of the piston toward its lower limit of movement. Just prior to the point at which such limit of movement is reached, the axial extension 88 of the piston will be impacted against the axial extension 19 of the ram 15 to drive the latter downwardly against the work to flatten the latter to remove dents and other irregularities.

When the piston 48 nearly reaches its lower limit of movement, air pressure will again be supplied to the space beneath the piston to move it upwardly. The reciprocation of the piston thus automatically continues so long as air is supplied through the hose 22, and the ram 15 will be constantly successively impacted against the work to flatten the irregularities therein.

At each upward movement of the piston 48, the upper end of such piston will be carried by its own inertia into engagement with the wall 31, thus causing a relatively light upward impact to be delivered to the cylinder 28 to relieve pressure on the ironing plate 88 against the work. Immediately, however, such upward impact is released the air pressure acting downwardly on the wall 31 reimposes the endwise elastic pressure tending to force the ironing plate 6:8 downwardly. Thus when reciprocatory pressures are imposed on the ironing plate 68 the rounded flange 69 tends to flatten out irregularities in the work. In this connection, it is pointed out that the pressure head assembly in Figure 4 is moved around relative to the Work, and accordingly the ironing plate travels over the work to assist in the smoothing operation. Movement of the ironing plate is facilitated by th fact that pressure of the plate against the work is relieved at each upper limit of movement of the piston 48 in the manner stated. Attention is also invited to the fact that the ram is carried by elements of the apparatus which are cushioned relativ to the tool holder, and in practice, therefore, it has been found that the ram has a tendency to gently machine the work surface rather than hammer it.

As previously stated, the pressure in the chamber 38 acting on the upper surface of the wall 31 tends to hold the cylinder 28 in its lowermost position with the ironing plate 88 in engagement with the work. When the piston 48 is moving upwardly, air pressure in the bottom of the cylinder 28 beneath the piston 48 also acts downwardly on the upwardly facing surfaces of the interior of the cylinder. This force is thus added to the force acting downwardly on the wall 31. The additional downward force is released during upward movement of the piston 48 when the exhaust ports 6| are opened, and the force acting downwardly on the wall 31 is at least partly counterbalanced during downward movement of the piston 48 by reason of the fact that the pressure acting downwardly on the piston 48 also acts upwardly against th bottom surface of the wall 31. The downward forces on the upper surface of the wall 31, however, are not completely counterbalanced since there is a relatively constant pressure in the chamber 38 which exceeds the pressure beneath the wall 31 due to the expansion of the space above the piston 48 during downward movement thereof.

Therefore, there is always present an elastic fluid pressure acting downwardly on the cylinder 28 and ironing plate 88. This pressure is greater during upward movement of the piston 48 than during downward movement for the reasons explained, but the net downward movement is always sufficient to elastically hold the ironing plate in contact with the work. However, the lighter downward pressure on the plate 68 during downward movement of the piston 48 permits the ironing plate to move slightly during such periods b the application of forces thereto laterally of the axis of the cylinder 28. Moreover, as previously stated, the light impacting of the piston 48 against the bottom of the wall 31 when the 7. pistonamoves 1 upwardly relieves pressure of: the ironingplatewfrom: the work, thus permitting the assembly to be; moved .over thework during such perioda.

We-claim:

1. Asheet metalstraightening apparatus comprising a cylindrical support-havinga closed end, a -cylinder mounted insaid support and projecting from the other end-thereof and axially movable relative to said support, a work-engaging mem ber carried by theprojecting end of said cylinder, an ainmotor carried by said cylinder therewithin and. includinga reciprocating piston, .a ram engageable With said piston and projecting from said cylinder within'said work-engaging member to :contactwiththe work, an air hose connected to said support and having an axial tube projecting into. said support, said cylinder having an opening, fitting saidtube to supply air to the interior of said cylinder in-any axially moved position thereof, said piston and said cylinder having portsand passages to supply air pressure alternately ag-ainst'opposite ends of said piston to reciprocate it, said cylinder. having a surface subjectto pressure .in said tubewhereby, during operation of saidmotor, said cylinder will be urged toward the work to maintain said work-:engaging member in contact therewith.

2. Apparatus constructed-in. accordance with claim 1 wherein said work-engaging member is in the. form of an ironing plate having an annular rib: of curved cross-sectional shape engageable with-the' work to effect an ironingaction thereon during operation of said motor.

3. A sheet meta-1 straightening apparatus comprising a'cylindrical support having. aclosed end, a cylinder mounted in. said support andprojecting-. from the. other end thereof, and axially movable relative to said support, a work-engaging member carried by the projecting end of said cylinder, anair motor carried by said. cylinder therewithin and including a reciprocating piston, a ram engageable with said piston and projectingfrom said cylinder within said work-engaging member to contact with the work, an air hose connectedxto'said support and having an axial tube.- projecting' into said/support, said cylinder having an opening fittin said tube to supply air to the interior of said. cylinder in any axially moved position thereof, said piston and said cylinder. having ports and passages to supply air pressure alternatel against opposite ends of said piston toreciprocate it, said cylinder having a surface subject to pressure'in said tube whereby; during;,operation.of said motor, said cylinder will be urged toward the work to maintainsaid. worken'gaging memberin contact therewith, a substantially; U-shapedarm having one end connected to said support, and aWork-engaging element carried by the other end of said arm and engaging thecsiderofthe workxopposite said work-engaging member;

4:;- Asheet metal straightening apparatus comprising a cylindrical support having a closedend and an open end, a cylinder mounted in'said support and projecting through the open endthere.- of', said cylinder being axially movablein said support and having a portion engageable therewith to: limit movement of said cylinder from the-open endof said support, a piston mounted to reciprocate in said cylinder, a cap carried by; said cylinder within said support and havingan axial chamber, a tubular projection carried by the closed end of Saidsupport and extending into said-.-axialchamber, a pressure air 'line communicating with said axial chamber throughsaid tubular projection, saidcap, saidcylinder and said piston having ports and passages for alter-.- nately supplying air pressure to the interior of said cylinder. at opposite'ends of saidpiston to reciprocate the latter, a work-engaging member carried by the projecting end of said cylinder, said axial chamber. having one wall thereof sub-.- ject to pressure-in said chamber to urge said cylinder from said support to maintain said work-.- engaging member inv engagement with the work, andarammounted in the projecting. end of said cylinder. and engageable with said piston and with the work to perform a smoothing operation on the latter.

5. Apparatus. constructed in accordance with claim 4 wherein said' work-engaging member comprises anironing plate through which said ram projects, and provided with a depending flange of curved cross-section surrounding said ram.

6. A sheet metal straightening apparatus comprisinga cylindrical support having a closed end and an openend, a cylinder mounted in said support and projecting through the open end thereof, cylinder being axially movable in said support and having a portion engageable therewith to limit movement of said cylinder from the open end of said support, a piston mounted to reciprocate in said cylinder, a cap carried by said cylinder within said support and having an axial chamber, a tubular projection carried by the closed end of said support and extending into said axial chamber, a pressure air line communicating with said axial chamber through said tubular projection, said cap, said cylinder and said piston having ports and pas sages for alternately supplying air pressure to the interior of said cylinder at opposite ends of said piston to reciprocate the latter, a work-engaging member carried by the projecting end of said cyl inder, said axial chamber having one wall thereof subject to pressure in said chamber to urge said cylinder from said support to maintain said workengaging member in engagement with the work, a ram mounted in the projecting end of said cylinder and engageable with said piston and with the work to perform a smoothing operation on the latter, an arm connected at one end to said support and having its other end terminating at the side of the work opposite said ram, and a work-engaging dolly carried by the last named end of said arm.

'7. A sheet metal straightening apparatus comprising a support having a cylindrical bore and provided with a closed end, a cylinder axially movable in said support and projecting from the other end thereof, a work-engaging member carried by the projecting end of said cylindenan air motor mounted within said cylinder and including a reciprocating piston, a ram engageable with said piston and projecting from said cylinder within said work-engaging member to contact with the work, a chamber in the upper end of said cylinder of substantially smaller diameter than said bore, and having a pressure surface'facing away from said other end of said support, a source of air under pressure, and means for supplying air from" said source to said chamber and including conduit means extending through the closed end of the support and having a sealed connection with said chamber, said piston and said cylinder havingports and passages to supply air from said chamber alternately against opposite ends of said piston to reciprocate it, said surface being subjected. to pressure in said source whereby said cylinder will be urged toward the work to maintain said work-engaging member in contact therewith.

8. A sheet metal straightening apparatus comprising a support having a cylindrical bore and having a closed end, a cylinder axially movable in said bore and projecting from the other end of said support, a work-engaging member carried by the projecting end of said cylinder, said cylinder having an axial bore, a reciprocating piston in such bore, a ram engageable with said piston and projecting from said cylinder within said work-engaging member to contact with the work, a cap carried by said cylinder and having a hollow axial projection extending into the axial bore of said cylinder and forming a pressure chamber having a pressure surface facing toward the firstnamed end of said support, a source of air under pressure, and means for supplying air from said source to said chamber and including conduit means extending through the closed end of the support and having a sealed connection with said chamber, said piston and cylinder having ports and passages to supply air from said chamber alternately against opposite ends of said piston to reciprocate it, said surface being subject to the pressure supplied thereto by said air supply means to urge said cylinder toward the work to maintain said work engaging member in contact therewith.

FRANK W. BOWIE.

EDWARD N. STURDEVANT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,661,194 Osborne Mar. 6, 1928 2,187,110 Champayne Jan. 16, 1940 2,263,423 Kattrein Nov. 18, 1941 2,282,111 Beckwith et al. May 5, 1942 

